broken penis?

ok so me and my boyfriend used to have sex a lot a lot, and it was totally fine, then he got sick and went on loads of medication so his dick couldn't get hard/ stay hard(understandable and it was fine because it was because he was ill) but now he's been off the medication for over a month and we can have sex once a day at most then his duck hurts?) he says its a sharp pain and we have to stop, has this happens to any of your men before and do you know why or how to stop it? thanks x